Transmission system comprising at least a satellite station and a connection station, a station including a speech message correction device and a method of improving the quality of speech messages.
The present invention relates to a transmission system comprising at least a satellite station and a connection station for connecting the system to a switched network, in which system at least one of said stations includes means for receiving speech messages transmitted in frames and a speech message correction device for modifying the speech signal frames as a function of the quality of the transmission.
The invention likewise relates to a station suitable for such a system, which station includes a speech message correction device for modifying the speech signal frames as a function of the quality of the transmission.
The invention also relates to a method of improving the quality of speech messages.
The invention finds interesting applications in the domain of portable radio telephones complying with the GSM and other standards (DCS . . . etc.).
Such a system is known from U.S. Pat. No. 5,687,184 in which at least one of the stations includes a message correction device which already notably improves the quality of the messages heard.
The present invention proposes a system of the type defined in the opening paragraph, which certainly still more improves the quality of the messages received in poor transmission conditions.
For this purpose, such a system is characterized in that the speech message correction device includes a counter of bad frames, an attenuation circuit for diminishing the amplitude of the speech signals for a count of said counter that is higher than a predetermined value.